Kinetic parameters for 7-ethoxy-4-trifluoromethylcoumarin O-deethylation by microsomes from COS-1 cells expressing wild-type and variant CYP2B6s
| Variant | Km | Vmax | Vmax | ||
|---|---|---|---|---|---|
| Protein | P450 | Protein | P450 | ||
| μM | pmol/min/mg protein | pmol/min/pmol CYP2B6 | μl/min/mg protein | μl/min/pmol CYP2B6 | |
| CYP2B6.1 | 5.50 ± 0.44 | 9.97 ± 1.70 | 3.93 ± 0.45 | 1.91 ± 0.43 | 0.72 ± 0.07 |
| CYP2B6.2 | 6.28 ± 0.51 | 8.85 ± 2.54 | 6.52 ± 0.77 | 1.42 ± 0.36 | 1.04 ± 0.08 |
| CYP2B6.3 | 6.36 ± 0.72 | 9.24 ± 1.93 | 6.31 ± 0.82 | 1.47 ± 0.32 | 1.01 ± 0.12 |
| CYP2B6.4 | 6.01 ± 0.55 | 12.7 ± 2.45 | 7.72 ± 1.04** | 2.10 ± 0.27 | 1.30 ± 0.20** |
| CYP2B6.5 | 5.71 ± 0.19 | 9.59 ± 2.07 | 6.60 ± 0.20 | 1.72 ± 0.42 | 1.16 ± 0.02* |
| CYP2B6.6 | 7.71 ± 0.29* | 17.7 ± 4.13 | 10.3 ± 0.54** | 2.31 ± 0.52 | 1.34 ± 0.07** |
| CYP2B6.7 | 7.53 ± 0.54 | 14.7 ± 4.16 | 9.70 ± 0.72** | 2.01 ± 0.60 | 1.31 ± 0.14** |
Each value represents the mean ± S.E. of four separate experiments derived from independent preparations.
3-178 p < 0.05, ∗∗ p < 0.01 versus CYP2B6.1.